Pneumatic cushion for sliding doors



(No Model.)

' J. P; RUNKEL.

PNEUMATIG CUSHION FORSLIDING DOORS. 7 No. 552,006. Patented Dec. 24,1895.

UNIT D STATES ATENT 'FFICE' JOHN P. RUNKEL, or MILWAUKEE, wIsooNsIN.

SPECIFICATION forming part of Letters Patent No. 552,006, dated December24, 189 5. Application filed May 8,1895. Serial No. 5&8519. (No model.)

To (ZZZ whom it may concern.-

Be it known that 1, JOHN P. RUNKEL, of Milwaukee, in the county ofMilwaukee and State of \Visconsin, have invented a new and usefulImprovement in Pneumatic Cushions for Sliding Doors, of which thefollowing is a description, reference being had to the accompanyingdrawings, which are a part of this specification.

My invention has relation to improvements in pneumatic cushions forsliding doors, particularly adapted, although not necessarily, forelevator-well doors.

The object is to provide a simple form of pneumatic cushion adapted tobe actuated to preventjar'or concussion either in the opening or closingof a sliding door, the device being particularly advantageous inconnection with an elevator-well door which is opened or closed by meansof spring action, such doors, under ordinary circumstances, beingparticularly subject to jar and concussion.

In the accompanying drawings, Figure 1 is a front elevation of anelevator-well door and the frame therefor, showing my improvementapplied to the hangers of the door. Fig. 2 is a longitudinal sectionalview of one of the cylinders shown in Fig. 1. Fig. 3 is an end view ofthe right-hand end of Fig. 2. Fig. 4 is a detail view of thescrew-valve, looking at the point of the valve and against the innerside of the head of the screw; and Fig. 5 is a fragmentary view of amodified form.

Like numerals of reference denote like parts throughout the severalviews.

Referring to the drawings, the numeral 7 indicates the front wall of theelevator-well 5 8 8,

the side walls thereof, and 9 the elevator-well door. Connected to thedoor are the usual hangers 10 10, in which are journaled rollers 11 11,traveling on the trackway 12. To the top connecting-piece 13 of thehangers are bolted end supports or legs 14 14 and lat 14 for cylinders15 15. Each inner support 14 is provided with an outwardly-projectinglug 16, having an opening therein communicating with a small openingthrough the center of the end support, said smaller opening having aconical valve-seat 17 therein. The aperture of the lug is threaded toreceive the threaded portion of a screw-valve 18, said screw-valvehaving an inner reduced unthreaded portion terminating in a conical end,which is adapted, when the valve is screwed in, to fit the valveseat,and thereby close the opening.

Each outer leg or support of a cylinder is provided with a centralopening to receive therein the outer end of the cylinder, said outer endbeing open.

In each cylinderis a piston-rod 19, the outer end of which extendsthrough the open end of the cylinder. The piston carried on the innerend of each rod consists of a metallic disk 20 and a leather packing 21,held against the face of said disk by means of a nut 22. This packing issomewhat smaller in diameter than the diameter of the disk, and hasprojecting outwardly from its periphery an annular flange 23, the edgeof which, when the piston is on its in stroke, is adapted to be forcedtightly against the inner wall of the cylinder by the resistance offeredby the air-pressure.

The top portions of the outer supports 14 14 are provided with aperturedlugs 24 24, through which passes freely a rod 25. The opposite ends ofthis rod are securely con nected to the respective outer ends of thepiston-rods by means of arms 26 26.

Projecting inwardly from the side walls 8 8 are arms 27 27 which areprovided upon their ends with rubber buffers or cushions 28 28.

- In the operation of my device, when the door is slid toward the arm 27for the purpose of opening the doorway, the end of rod will contact withthe rubber buffer or cushion of said arm, and thereby force the rod 25in an opposite direction to that of the travel of the door and cause thepiston in cylinder 15,

by reason of its piston-rod being connected up to the rod 25, to travelinward, while the piston in cylinder 15 is simultaneously made to traveloutward. When the door is subsequently closed, of course the reverseoperation takes place that is to say, the left-hand end of rod 25contacts with the rubber buffer or cushion of arm 27, and the piston ofcylinder 15 is forced inwardly, while the piston of cylinder 15 issimultaneously forced outwardly.

It is advisable that the screw-valves 18 be at the adjustment indicatedin Fig. 2 to permit of the-escape of a small quantity of air.

ble-cylinder arrangement, wherein instead of employing only one rod 25above the cylinders an additional rod 25 is used, arran ged be low thecylinders and passing through suitable openings therefor in the outersupports 14 14.

Instead of the connecting-arms 26 26 used in the form illustrated inFigs. 1 and 2, I employ longer arms 26 26, which extend down to andconnect with the ends of the rod 25.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In a pneumatic cushion for sliding doors, the combination, ofcylinders carried by the door, each of said cylinders having one endopen,pistons within the cylinders having their piston-rods projectingthrough the open ends of the cylinders, a device slid ingly mounted tomove with the door, said device having connection with the respectivepiston rods to cause said rods to move in unison, and buffers located inthe path of movement of the connecting device, substantially asdescribed.

2. In apneumatic cushion for sliding doors, the combination of cylinderscarried by the door, each of said cylinders having one end open, pistonswithin the cylinders having their piston rods projecting through theopen ends of the cylinders, a rod slidingly mounted to move with thedoor, said rod having connection with the respective piston rods tocause said piston rods to move in unison, and buffers located in thepath of movement of the connecting rod, substantially as described.

3; In a pneumatic cushion for sliding doors, the combination, of a door,hangers secured thereto, rollers journaled in the hangers, a track-Wayfor the rollers, supports secured to the connecting piece of thehangers, cylinders carried by the supports, said cylinders having theirouter ends open, pistons within the cylinders, the rods thereofprojecting through the open ends of the cylinders, a device slidinglymounted to move with the door, said device having connection with therespective piston rods to cause said rods to move in unison, and buiierslocated in the path of movement of the connecting device, substantiallyas described.

In testimony whereof I afiix my signature in presence of two witnesses.

JOHN P. RUNKEL.

\Vitnesses:

ARTHUR E. lVIoRsELL, ANNA V. FAUST.

